capax infiniti
by ivyandtwine
Summary: '"You like museums right?" Well. she hadn't been expecting that.' A season 2 fic set the week after The Third Man (2x14)
1. Chapter 1

_A/N: This is from a prompt on castlefanficprompts - 'pre couple, they go to a museum'_

* * *

A large coffee cup gets placed in front of her, and she glances up to see her shadow drop down onto his seat next to her desk. She immediately reaches for the cup, welcoming the break from the large piles of paperwork she has to get through today. She takes a sip, savoring the warmth, her usual flavors of vanilla interspersed with the coffee making her tastebuds hum.

"Hey," he starts, leaning back into the chair. She didn't think he'd be in today - there was no body drop so far, and he expresses his distaste for paperwork often enough that she's come to accept how eager he is to avoid it.

"Hey. Thanks for the coffee, Castle," she replies. "You dodging writing responsibilities again?"

"Nope. Ah, well, yes. But not the main reason I'm here. I have a favor to ask you."

She squints, wondering if this will end up with him asking her to use police resources illegally. But he looks excited, and his eyes light up when she gestures for him to go ahead.

"You like museums right?"

Well, she hadn't been expecting that.

"Uh, yeah, I do," she answers, her voice uneven, thrown off by his question.

"Great. I have two tickets for the opening of the new exhibit at the Natural History Museum, and Alexis can't come because she's got plans with friends. Please say you'll come? It's this Friday night." He looks at her, deep blue eyes pleading, and he is definitely sticking his bottom lip out on purpose. From the way her heart rate has sped up, his gaze may be working, so she purses her lips and looks down, avoiding his stare as she thinks it through.

She does love museums, she used to go a lot when she was younger, but uncertainty simmers in her stomach. It sounds like it's in the territory of a date, and she's not sure she's ready for that. _Not yet at least_.

"I don't know, Castle."

"Come on, Beckett. We had fun on our date last week right?" he says, grinning.

"That was _not_ a date," she splutters.

"And this isn't either, if that's what you're worried about. Just two friends enjoying an event, looking at some cool dinosaurs." He raises an eyebrow, and she laughs. Of course that would be his selling point.

She ponders on it for a moment, and mentally weighs up the pros and cons. Imagining herself and Castle going to such an event doesn't fill her with too much dread, and rather anticipation rushes throughout her body. She taps her fingers along her jeans, knowing she is killing him with this mental torture, but in the end finds herself gravitating to a yes.

Because damn, she _does_ like museums, and she hasn't been to one in so long.

She bites her lip, her teeth peeking through as she struggles to suppress her smile. "Okay, fine."

The exclamation of joy that erupts from his lips is enough to convince her that she made the right decision, and his happiness becomes mirrored in her now exposed smile. She shakes her head as he pumps his fist, but she revels in his joy as she relaxes back into her chair.

Since the Coonan case, since he almost left the precinct, left _her,_ she wants him to know she appreciates having him here, that his happiness is important to her. He calms quickly, probably not wanting to scare her off, and grips the armrests as he relaxes his body back into the chair. His face has softened, but his bright eyes bore deep into hers with gratefulness, and her hand twitches in her lap, wanting to reach out and grab his.

"But no limo." She goes for light, teasing, saving the deep emotional reactions for another time. She doesn't need a limo, she prefers casual over the extravagance that she knows he could be capable of.

"Deal," he agrees, standing from his chair - apparently this was his only task for today. "But it's black tie, Beckett. Do you need me to buy you a dress again?"

She huffs. "Definitely not." As much as she liked the dress he bought her last time, the thought of him seeing her in a new dress, the way his eyes would roam-.

"-Great. I'll pick you up at seven?" he asks, breaking her fantasy, and she nods in return, her mouth dry and her skin prickly with thoughts of dresses and dates - _not dates - _and she smiles to herself as he walks away.

Going to a museum with Castle? Okay, she may be a _little_ excited.

* * *

She's touching up her lipstick when she hears the knock on her door. Her outfit for tonight is a floor length black dress that hugs her curves and displays far more of her back than she's used to. Lanie had insisted that they go shopping together when Kate had mentioned the event to her, and they'd gone out in their lunch break yesterday to find her something to wear. When Kate had stepped out of the dressing room wearing it, the gasp that her friend had let out was loud enough to turn heads of other customers. Despite Lanie mentioning how great the dress would look on the floor of Castle's place, she had convinced her to buy it, raving about how beautiful she looked and how well it suited her figure.

Dark red lipstick, and curled hair complete her look and she can't help but feel elegant, as she looks at herself in the mirror, her fingers soft as they trace the neck of her expensive dress. Butterflies flit in her stomach as she walks to the door, dress swishing and heels clicking on the floorboards.

She opens the door and is met with Castle standing there in a sleek tuxedo, and she has to pause and take in the sight of him. He looks _good._ His hair is gelled-up a little, and hands are in his pockets, clenching like he's not sure what to do with them.

Her mouth goes slack, and the butterflies are dead now, burned by the fire that has come alight inside her.

They both are silent, staring at each other in a state of dress that they rarely have seen. His eyes roam over her, his jaw slightly ajar and his irises dark, spreading tingles throughout her body with his gaze, and she wants to push him away and pull him towards her bedroom at the same time.

She shifts, trying to the shake the latter feeling away, because his stare and her reactions are much too serious for this 'not a date' evening.

"Kate, wow. You look incredible," Castle says finally, and her stomach flips with the compliment. She's glad she bought the dress.

"Thank you, Castle." She gives him a small smile. "You- uh, don't look so bad yourself." Kate clears her throat, hoping she appears calm and collected on the outside. "Want to come in?"

She gestures inside and he steps through her doorway so she can close it behind him.

He returns her smile and then starts to look around at her apartment, surely trying to take in as much as he can while he's here.

"I'm just gonna grab my bag and then we'll go?" she asks, and he nods, eyes darting back to her, and then flicking around the room before coming to rest upon her again. She can see he's conflicted between staring at her and investigating the trinkets lined up on her shelves, and so she rolls her eyes and makes the decision for him.

She turns to her bedroom and she hears him suck in a breath. _Oh._ He must have seen the back of her dress. She swings her hips a little as she walks, lips smirking and body thrumming, enjoying the power she holds over him in her formal attire.

Kate grabs her bag, a black clutch that unfortunately does not have room for her gun, and checks the mirror one last time. She spritzes herself with some perfume, hints of vanilla and musk settling onto her skin, and she walks back out to meet Castle.

He's apparently taken it upon himself to check out her entire book collection, body hunched over as he skims his hand along the titles, and ok, they need to go before he finds the book that he signed all those years ago.

She watches for a moment, enjoying the way his jacket has tightened across the breadth of his shoulders, and laughs quietly as he scrunches his face up at her collection of Patterson novels.

"Come on, Castle, let's go."

He straightens up at her voice, and walks briskly over as she goes to grabs her coat from the closet. He's behind her before she can even start to put it on and she inhales at the feel of him so close, his hands reaching for the coat to take it from her. He holds it up and she slip her arms through and she has not let out the breath she's been holding this whole time. Once it's on he carefully lifts her curls out from the collar, fingers brushing her neck, causing goosebumps to form. She reminds herself to _breathe,_ but her exhale comes out louder than she wants, and her skin flushes as she hopes he doesn't notice. They exit her apartment and make their way to the elevator, Kate trying to block any more involuntary reactions her body may decide to have.

Because putting on coats and getting goosebumps are things that happen on dates.

And this was _definitely_ not a date.

* * *

While not a limo, he did call the town car for transportation, and she had found herself enjoying the comfort and easy ride. Expensive leather seats and room to stretch her legs shifted her appreciation for this lifestyle, and she had relaxed as her and Castle shared small talk in the car.

Now, as she steps out in front of the museum, she realizes that anything less than the sleek town car would have looked out of place. Large banners, bright, colourful lights, and a small amount of press decorate the entrance. It's not as overwhelming as the Heat Wave book launch though, and her shoulders relax as she takes it all in.

Castle comes around the back of the car to meet her and lifts his elbow out for her to hold. She loops her arm through and rests her palm in the crease of his elbow, the heat from his body seeping into her palm, and any hesitation she had from this action last week has dissipated as they walk up the stairs and through the entrance.

Coats are checked and they are immediately presented with tall glasses of champagne. Kate sips the liquid, relishing the sweet taste and burst of bubbles as they slide down her throat.

The entrance room holds a large Barosaurus, and no matter how many time she has been here, she always enjoys gazing at the height, marvelling at the way scientists have managed to recreate the creature from its bones.

"You know, Beckett, it is night time. Who knows what exhibits may come to life here," he jokes, his eyes dancing with mirth as she turns to face him.

She laughs, rolling her eyes. "That was a movie Castle, I don't think any capuchin monkeys are gonna come wandering out to make friends."

"But you have to admit, it would be fun."

"Hmm, yes," she agrees, "I do think that playing fetch with a T-Rex would be pretty entertaining."

Her eyes are alight, and she glances to his to see a similar expression in his, the banter outside of the precinct causing a smile to bloom on both their faces. She's enjoying herself so far, Castle is proving himself great company, and the rigidity that had worked it's way through her body was evaporating by the minute.

They wander around the large room, their discussion light, mostly work related. Occasionally acquaintances of Castle's walk over to mingle, ones who pretend to know more about him than they actually do. He introduces her every time, complimenting her in different ways, her work, her beauty, and she can see his eyes glow each time he gets to show her off. While not exactly one to like bragging, his compliments cause the butterflies to fly back in, flapping their wings furiously inside her. His enthusiasm and delight as he gets to talk about her feels more important that the actual words he is saying, she's left speechless so often that she doesn't even try to stop his words.

They are called into a new room for the official opening, and as they walk through, she cranes her neck up to see a blue whale strung from the roof, encompassing the large space above them. It's huge, this magnificent creature, and her mouth opens as she stares in wonder. Most people around her are doing the same, needing to take in the enormous creature as it spans the length of the room.

Kate looks around, wanting to share her marvel with Castle, but can't see him immediately on either side of her. She jumps as she feels Castle's hand pressing into her bare lower back as he guides her further in to follow the crowd. The touch of his skin directly to hers causes her pulse to quicken and she has to prompt herself to breath as his hand is jostled from their movement and his fingers delicately brush her spine as they walk.

"Pretty amazing, huh?" he leans down and whispers near her ear, though her focus has been torn away from the whale now. It's not that quiet in the room, so she's not sure why he feels the need to whisper, but his breath skates her ear, and goosebumps trail down her neck. She sips her drink, needing liquid for her suddenly parched mouth.

She nods, ignoring her body's reactions, and yeah, it's amazing. She's seen the whale plenty of times, but the atmosphere of the room adds to the reaction; the blue and purple lighting that sweep the room, flashing and flickering in patterns, the embellished stage for speeches creating a focal point. The elegance of the evening creates a magical vibe, and she can't help but smile up at him, eye crinkling and teeth on display. She flicks her eyes to his lips and back up, a wave of desire sweeping over her, and she blinks and turns away, a small smile resting upon her face.

He drops his hand from her back once they've settled to face the stage, and she immediately misses the heat that radiated from his hand. Disappointment, and subsequent confusion with herself, form a tornado in her stomach, but she pushes them down for now, pulls her focus back to him and the buzzing in the room as a man steps on stage. She squeezes his arm briefly in thanks, and shifts closer to him, shoulders touching as they turn their attention to the speeches that are about to commence.

He's right. Tonight is amazing.

* * *

_Thank you for reading. This will be a two shot, the next chapter will be posted tomorrow or the next day. _

_A huge thank you to Lou for betaing, and Moana for coming up with the title. _


	2. Chapter 2

The exhibit was officially opened. Kate stood close to Castle throughout the speeches - various men and women giving spiels about the importance of the museum. She suspects he was paying closer attention to her reactions than the actual content, from the way he had side-eyed her throughout. He'd constantly whispered in her ear various jokes and sarcastic comments, making her laugh, or bump his shoulder when he was being inappropriate. His actions were not helping to alleviate the mess of emotions crowding her mind. Thoughts that she's only ever briefly entertained were now creeping into her mind, weaving themselves into daunting yet exciting possibilities.

They were now invited to go look at the new collection; a feature on reptiles, but as they walk with the crowd, Castle slows down their pace to hang back as the crowd passes them, her brow creasing as she silently questions him.

"Why don't we go look at the other exhibits while they aren't as crowded?" he says, and she nods slowly, mouth opening with understanding. She's not exactly one for huge crowds, usually enjoys museums when they are quiet and hence won't feel rushed to work her way through.

She casts her eyes to his, excitement rattling her body at the thought of touring the museum alone with Castle, and on an impulse grabs his hand before he can say anything, and quickens their pace to lead him out another exit.

"Come on, Castle, let's go see some dinosaurs."

* * *

"Did you know that the brain of the stegosaurus was about the size of the walnut?" Castle says, eyebrows raised as he flourishes his hands towards the dinosaur in question, apparently trying to impress her with dinosaur facts.

"I did, actually. In fact, I believe that scientists thought that they had a second brain for a while, because their main one was so small," she challenges back, her tongue pressed through her teeth as she turns to face him.

He raises his eyebrows, his gaze sweeping her face as his lips blossom into a smile, and ah, it seems she is the one to impress him. "I did not actually know that, well done, Detective Beckett."

A smug smirk graces her face, happy with her win. Kate relishes challenging him, and the way his face is alight, she knows he's feeling the same way. She walks ahead before their stare becomes too intense - again - her fingers intertwined and fidgety as her heels scrape along the floor.

Castle strides up quickly beside her, rarely letting them separate too far, but she finds it pleasant to have him close, shoulders brushing as she turns to him to point something out, listening to Castle's voice in her ear as he makes up stories about dinosaur feuds and romances.

His glee radiates from him as he gets excited at almost every dinosaur while they walk through, childlike happiness pours out of him and onto her. She can't help but catch his positivity, and she revels in the warmth and joy that she feels from watching him spout off facts and anecdotes. It's precious, she finds herself thinking, and she imagines him as a father, how lucky Alexis is to grow up with his enthusiasm.

"You used to come here with Alexis?" she asks, as she watches him gaze at a Triceratops.

"Yeah, all the time," he answers. "She loved it, we would always go to the kids events and activities, she would absorb all the information right up." He smiles, eyes dazzling as he remembers, and she softens further. Her hand reaches up to clutch at her mom's ring, but grazes her skin instead and she remembers she decided to forgo it this evening. His story reminds her of her own childhood, and she presses her hand to her chest as she listens to him spout off a story about a digging for dinosaur bones event that he had brought Alexis to.

"Sounds like you guys had a great time, Castle."

"Yeah, we did. Your parents ever take you?" he asks, cautiousness tracing the question, but his eyes long for information from her. She bites the inside of her cheek and looks down, but wants to share with him, even if it's small.

"Yeah all the time, especially when I was younger. Mom loved museums as well."

A smile stretches across his lips, gratitude pouring from his eyes, but doesn't press her for more like she was expecting, and she throws him a grateful look. Her heart clenches, at him or the thought of her mother, she's not sure.

Maybe both.

She nudges him with her elbow and walks on ahead of him, surprised when he's not immediately at her heels but rather giving her some space as she reminisces.

She's been gazing at a pteranodon for a few minutes - the flying dinosaurs having always been some of her favorites. She's fascinated by the way she can see the link between these extinct species and today's reptiles and birds. She skims her hand over the information card, learns that their wingspan could reach up to 18 feet.

She twists her head up, eyes searching for Castle to share the fact with him. He's close, sliding up behind her, and she points to the fact on the card for him to read. Heat emanates from him, the warmth on her exposed back too much and not enough. Her ribs contract and her brain goes fuzzy, dinosaurs and wingspans suddenly lost from her mind.

"You like this guy?"

"What? Oh. Yeah. I love the flying dinosaurs," she manages, swallowing around the lump that has formed in her throat. She shakes her head, trying to focus on something that is not the mystery writer crowding her. Her body buzzes, she can hear her pulse, so loud in her ears she questions whether he can hear it as well.

Come on, Kate. Control yourself.

"Me too. Such a cool mix of birds and reptiles," he says, mirroring her earlier thoughts, and her lips turn up as she hums, nodding her head and trying to drag her mind back to the display.

Kate shifts, putting space between them before she overheats or he notices how unfocused she is right now. She really needs to get a hold of herself - tonight is _not a date_, she reminds herself, bodily reactions be damned. She _has_ been feeling warmer towards him lately; after last week, and after Dick Coonan, but thoughts of going on dates, of _relationships_, make her heart plummet and lift with excitement at the same time.

Is she ready for something more?

"Where to next?" he asks, breaking her out of the dangerous swirl of thoughts, and she looks around, realizes that they've reached the end of the dinosaur hall.

She searches her memory for the other exhibits that she loved, and oh, _yes_, she knows where she wants to go.

Her fingers jerk, she wants to grab his hand like earlier, and lead him to her favorite hall, but she's second guessing herself now. She makes a fist, knuckles whitening, unsure if he'll misinterpret the gesture, or worse, if his interpretation is _exactly_ what she wants.

Screw it.

She reaches down to his hand, laces their fingers together before she can further question her actions. She tugs him out of the room and to the stairs, his deep yet bright laugh making her heart do tumbles in her chest.

* * *

A wide smile is plastered on her face as they enter the Hall of African Mammals, the centre feature displaying several African Elephants. Their hands are still knotted, palms getting hot, but she can't bring herself to let go. They walk up to the display, gazing upon the magnificent creatures, and Castle grips her hand even tighter as she stares up at the animals. She's been a fan of elephants for a while, her mom loving them too, and when she died she fell in love with them a little more. They remind of home, of family, and has to stop herself from reaching up and touching the beautiful grey mammal.

"You like elephants?" he asks quietly, the tenderness in his voice causing her eyes to close and her body to sway towards his. "I mean I know you have them on your desk, but, uh, is there a story there Beckett?"

"Yeah, I- My mom. She liked them," she murmurs, and untangles their hands as she turns to face him. She meets his eyes with a slightly strained smile, hoping he can see the apology for breaking their contact written on her face. The memories of her mom have laced the evening, not the main thing crowding her brain, but it's built up enough that she needs space for now.

He nods in understanding, steps to the right to leave a small gap between them. It's silent, the room still as they look at the elephants and read the fact cards.

"Ever been to Africa?" he asks, breaking the silence.

"No." She shakes her head but smiles. "It's would be a dream to go though, see a safari. I think it would be… indescribable. You?"

"No, never been. Maybe I'll take you one day Kate."

She can tell he's trying to make it a joke; his eyebrows raised and eyes bright, but her heart tingles at the thought, and the feeling disperses to the tips of her fingers and toes.

Oh. Wouldn't that be _incredible_.

"I think that would be pretty great, Castle," she returns, her smile widening with her sincerity, and his whole face lights up, his chest expanding and shoulders straightening. "I'd just have to keep you from wandering off and getting eaten by a wild animal."

She shoves her shoulder into his as his jaw drops from her joke, and she leaves him there as she ventures over to look at the display of lions, the sound of her heels echoing throughout the empty room.

She looks back, he hasn't moved, but he's watching her with what looks like adoration, and she flicks her head back straight before she stares too long. Kate tries to read about lions, but her brain keeps wandering; the vision of traveling with Castle seems like it's going to be stuck in her head for a good while.

* * *

They'd finished the African Mammals and then decided that they should look at the exhibit they actually came here for before calling it a night. The exhibit was spectacular, and they'd marveled at the various reptiles on display. The museum had even brought in a live snake for the evening, allowing people to hold it for photos, and Kate had shocked Castle as she volunteered to have it wrapped around her arms. She was never one to be scared of snakes, and the photos that Castle took showed her absolutely radiating with joy.

They're walking back to her place now, Castle having asked the town car to drop them a little further away, claiming it was easier parking, but she knew he was wanting to prolong the evening. She hadn't protested though, because as much as she didn't want to admit it, she wasn't too fond of it ending either.

Their hands brush as they walk and she's about to stretch her fingers and hold onto his like earlier in the evening, when she feels his large fingers twining through hers. Her heart picks up, and she sinks her teeth into her bottom lip - the gesture suddenly feeling more intimate than before. Still, she grasps his hand tighter, and feels him relax when she doesn't pull away, and he brushes his thumb over her skin as if to thank her.

It's cold tonight, her breath coming out as fog from the New York winter, but heat blooms from their clasped hands and she has a sudden craving to wrap her arm around his waist and lean into him.

"I had fun tonight, Castle," she says, her voice quiet but clear. "Thank you for bringing me."

He squeezes her hand and her breath stutters. "It was my pleasure, Kate."

That's the third time tonight he's used her first name, and it make her heart clench, longing to hear him say her name like that more often.

He stops and her brow furrows, she searches his face to find out why. He looks up and she follows his gaze and realizes they've reached her building, indicating that their evening has come to an end.

She angles her body towards him, hands still locked together, and she smiles up at him, their faces close. Her brain fogs at his proximity, and she doesn't even try to make an excuse for her reaction. Their eyes lock and she quickly flicks hers to his lips and back up, and oh, she should _not_ have done that, because all she can think about is his lips on hers. Her heart is wild in her chest, but she's panicking, her brain running in circles. She licks her lips and can see his gaze is drawn to them, but no, this is getting too much, it's too soon, right? Her brain wins out, and she pulls her head back before she does something stupid like lean in.

"Thanks again, Castle," she says, and reluctantly slips her hand from his, turning to walk to her door. Her heart is protesting, her breathing rapid. The disappointment lacing his eyes makes her pause-

"Kate, wait," he calls, and before she knows what's happening he has grabbed her hand again and pulled her back to him. His other hand clasps the back of her neck and he leans in and-

Oh. He's kissing her.

His lips brush hers softly at first, giving her an out if she wants it, but she doesn't. She deepens the kiss, drinking from his lips and she sucks his bottom lip into her mouth. He lets out a moan, the noise reverberating through her whole body, and she wants to pull that sound from him again and again. Her legs feel numb, her knees weak, and waves crash in her chest as she struggles to breathe. One hand is still tangled with his, squeezing tight, but her other has come up to clutch his bicep, and she's glad she's holding onto something because her head is _spinning_ from the feel of his lips. His other hand in her hair now, sifting through her locks and brushing her scalp. Electricity is shooting from his fingers, his lips, reverberating through her body, and oh, now _she's_ moaning. The kiss slows, and he draws away - _no_ \- but he rests his forehead on hers and the intimacy of it makes her heart surge. Her body is thrumming, her mind blank but also roaring, buzzing, and she bites her lip, tasting remnants of him there, and she can't help it as her face breaks out into a grin.

"I had a incredible date tonight, Kate."

Her mouth opens, about to protest against his words but decides against it, her lips splitting into a smile instead.

"Yeah, me too."

* * *

_capax infiniti - holding the infinite_

* * *

_Thank you for reading_

_And if you haven't already, feel free to check out my tumblr_

_it's _

_castlefanfics_

_:P_

_xo __Alex._


End file.
